Problem with GridBagLayout

[Daniel]

Hi, Im trying to make a GUI for a docking control program. It comprises of 4 text boxes at the top, then 8 buttons under these.
The text boxes have to be done using a BoxLayout, and the buttons using a GridBagLayout. They must then both be put in a JPanel.
I have got the text boxes sorted, and have been doing a lot of reading on how to make GridBagLayouts. I think the code I have should have the layout made. I belive the problem is that the GridBagLayout is hiding somwhere behind the panel I wish to put it on.
I have tried a few ways of putting the GridBagLayout on the panel, but it isn't having any of it!

Code:

 -----------------------------------------------------
 | Text Box 1                                        |
 |---------------------------------------------------|
 | Text Box 2                                        |
 |---------------------------------------------------|
 | Text Box 3                                        |
 |---------------------------------------------------|
 | Text Box 4                                        |
 |---------------------------------------------------|
 | Button             | Button  | Button  | Button   |
 |---------------------------------------------------|
 | Button             | Button  | Button             |
 |------------------------------|                    |
 | Button                       |                    |
 |---------------------------------------------------|

Code:

import javax.swing.*;
 import java.awt.*;
 import java.awt.event.*;
 import java.awt.color.*;
 import java.applet.Applet;
 
 public class GUI extends Applet
 {
     JFrame frame;
     
     // TEXT FIELDS
     JTextField seaShipsID;
     JTextField queueShipsID;
     JTextField dockShipsID;
     JTextField shipMessages;
     
     // BUTTONS
     JButton dockFromSea;
     JButton dockFromQueue;
     JButton setSail;
     JButton queue;
     JButton admit;
     JButton dequeue;
     JButton refuse;
     JButton bye;
     
     // PANELS
     JPanel textFieldPanel; 
     JPanel mainPanel;
     
     // GRID BAG LAYOUT
     GridBagLayout buttonLayout;
     GridBagConstraints buttonConstraints;
     
     public static void main(String[] args)
     {
         GUI gui = new GUI();
         gui.go();
     }
       
     public void go()
     {
         frame = new JFrame();
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
         
         buttonLayout = new GridBagLayout();
         buttonConstraints = new GridBagConstraints();
         
         textFieldPanel = new JPanel();
         textFieldPanel.setBackground(Color.lightGray);
         textFieldPanel.setLayout(new BoxLayout(textFieldPanel, BoxLayout.Y_AXIS));       
         
         mainPanel = new JPanel();
         mainPanel.setBackground(Color.lightGray);
         mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.X_AXIS));       
         
         // BUTTONS                      
         dockFromSea = new JButton("Dock From Sea");
         dockFromQueue = new JButton("Dock From Queue");
         setSail = new JButton("Set Sail");
         queue = new JButton("Queue");
         admit = new JButton("Admit");
         dequeue = new JButton("Dequeue");
         refuse = new JButton("Refuse");
         bye = new JButton("Bye");
         
         // BUTTON LAYOUT
         buttonConstraints.fill = GridBagConstraints.BOTH;
         addComponent(dockFromSea, 0,0,2,1);
         
         buttonConstraints.fill = GridBagConstraints.BOTH;
         addComponent(queue, 0,2,1,1);
         
         buttonConstraints.fill = GridBagConstraints.BOTH;
         addComponent(admit, 0,3,1,1);
        
         buttonConstraints.fill = GridBagConstraints.HORIZONTAL;
         addComponent(admit, 0,4,1,1);
         
         buttonConstraints.fill = GridBagConstraints.BOTH;
         addComponent(dockFromQueue, 1,0,2,1);
         
         buttonConstraints.fill = GridBagConstraints.BOTH;
         addComponent(dequeue, 1,2,1,1);
         
         buttonConstraints.fill = GridBagConstraints.BOTH;
         addComponent(refuse, 1,3,2,2);
         
         buttonConstraints.fill = GridBagConstraints.BOTH;
         addComponent(setSail, 2,1,3,1);
            
         
         // TEXT FIELDS
         seaShipsID = new JTextField("ID of boats at sea");
         queueShipsID = new JTextField("ID of boats in queue to dock");
         dockShipsID = new JTextField("ID of the boats in dock");
         shipMessages = new JTextField("No Message");
         
         // TEXT FIELD PANEL IMPLEMENTATION
         frame.getContentPane().add(BorderLayout.NORTH, textFieldPanel);
         textFieldPanel.add(seaShipsID);
         textFieldPanel.add(queueShipsID);
         textFieldPanel.add(dockShipsID);
         textFieldPanel.add(shipMessages);
                      
         // MAIN PANEL IMPLEMENTATION
         frame.getContentPane().add(BorderLayout.NORTH, mainPanel);
         mainPanel.add(textFieldPanel);
        
         frame.setSize(300,200);
         frame.setVisible(true);
     }
                 
         private void addComponent(Component component, int row, int column, int width, int height)
         {
             buttonConstraints.gridx = column; 
             buttonConstraints.gridy = row;
             buttonConstraints.gridwidth = width;
             buttonConstraints.gridheight = height;
             buttonLayout.setConstraints(component, buttonConstraints);
             add(component);
         }
     
 }

Thanks.

Daniel

[Albert]

I'm not sure if that is the problem but by implementing ActionListener you'll need to have an implementation for that method.

Greetings.

Albert

[Felissa]

I would recommend adding an ActionListener to each individual button, thereby deleting the need for the memory check and cleaning up your code.

Greetings.

Felissa